IDEs are useful for this. Let them keep track of minutia like syntax rules and names of common but differently-named methods. I find also find that it only takes me about a day of picking a language back up to remember which way they've gone on most of these things.

This kind of gets at what I think is the big advantage of learning a bunch of languages: it gives you instincts for which things are minutia and which aren't. The things you listed that every language has but does differently, which are annoying to figure out and remember, that's the minutia.